JPH0788573B2 - Film formation method - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a film forming method using an ion milling technique.

[Technical background of the invention]

Conventionally, a film forming method using an ion gun is performed, for example, as shown in FIG. First, from the ion gun 1
Ar ions 2 are emitted and collide with a target 3 provided facing the ion gun 1. The Ar ions 2 knock out the sputtered particles 4 from the target 3. Sputtered particles 4 are
A predetermined thin film is formed by depositing on the substrate 5 provided so as to face the target 3.

[Problems of background technology]

In such a conventional method, the sputtered particle emission surface of the target 3 needs to be arranged to face both the surface of the ion gun 1 and the substrate 5, that is, the film formation surface. In this case, Ar ion 2 causes target 3
In order to surely deposit the sputtered particles 4 hit out by the method on the surface of the substrate 5, it is necessary to appropriately set the incident angle of the Ar ions 2 with respect to the sputtered particle emission surface of the target 3 and the emission angle of the sputtered particles 4. Therefore, the space for disposing the target 3, the ion gun 1, and the substrate 5 cannot be reduced.
In particular, as shown in FIG. 1, the ion gun 1 and the substrate 5 have to be arranged with a certain distance. As a result, there is a problem that the device becomes large.

Further, in the conventional method, since the ion gun is provided so as to face the sputtered particle emission surface of the target 3, the sputtered particles that have been knocked out easily enter the ion gun 1 and easily cause contamination or electrical short circuit. . As a result, there is a problem that a high quality thin film cannot be formed. In particular, this problem also hinders the reduction of the space for disposing the ion gun 1 and the substrate 2.

[Object of the Invention]

An object of the present invention is to provide a film forming method capable of easily forming a high quality thin film with a small device.

[Outline of Invention]

The present invention is a film forming method that employs a means for depositing only sputtered particles on a substrate by causing ions to deflect while colliding with a target, thereby making it possible to easily form a high-quality thin film with a small-sized apparatus. is there.

Example of Invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, as shown in FIG. 2, a target 11 made of the material of the thin film 10 to be formed is prepared, and an ion gun 12 is installed around the target 11. A substrate 13 which is an object to be processed is placed facing the sputtered particle emission surface of the target 11. An electromagnet 14 is arranged behind the back surface of the substrate 13 which is back-to-back with the sputtered particle emission surface.

Then, for example, Ar ions 16 are emitted as ions for knocking out the sputtered particles 15 from the ion gun 12. Then
An electric field is generated by energizing the electromagnet 14 while controlling a predetermined current. By changing the strength of this electromagnetic field by controlling the current, the flow of Ar ions 16 is deflected, and the Ar ions 16 are caused to collide on the sputtered particle emission surface of the target 11 in a scanning manner. Here, the acceleration voltage of the Ar ions 16 is preferably set in the range of 400 to 500 V in consideration of the sputtering efficiency. When the Ar ions 16 collide with the sputtered particle emission surface, the target particles 15 are knocked out from the target 11, and the hit target particles 15 are deposited on the surface of the substrate 13 to form the thin film 10.

As described above, according to this thin film forming method, since the Ar ions 16 are deflected and collide with the target 11, sputtered particles are generated.
It is possible to set the scattering direction of 15 and the flow of Ar ions 16 flowing into the target 11 in opposite directions. As a result, the sputtered particles 15 are prevented from entering the ion gun 12 to cause contamination or an electrical short circuit, resulting in an extremely high quality thin film 10.
Can be formed.

Further, as shown in the drawing, by deflecting the flow of Ar ions 16 by about 180 °, the target 11 only needs to face the substrate 13, and the target 11 and the ion gun 12 can be arranged in parallel. . Therefore, the target 11, substrate
It is possible to provide a small-sized film forming apparatus by reducing the arrangement space of 13, the ion gun 12, and the electromagnet 14 as small as possible.

As shown in FIG. 3, as a means for deflecting the flow of Ar ions 16, instead of the electromagnet 14, a deflection plate 17 is provided so as to surround the target 11 and the substrate 13, and an anode voltage is applied to this. It is also possible to use a device that changes the electric field.

Further, as shown in FIG. 4, an ion gun 19a is provided so as to surround the target 18, and an ion gun 19b is also provided at the center of the target 18, and the substrate 13 is installed so as to face the target 18 and the sputtering is performed. Deposition of particles 15 and Ar ions 20
It is also possible to form the thin film 10 of extremely high quality by simultaneously performing the etching process by. That is, the Ar ions 16 emitted from the ion gun 19a on the outer side are collided with the target 18 while being deflected by the electromagnet 14 to knock out the sputtered particles 15 and the substrate 13 opposite to the target 18.
To deposit. During this deposition process, for example, Ar ions 20 are emitted from the central ion gun 19b toward the substrate 13 at the same time, and the deposited layer formed by the sputtered particles 15 is etched.
At this time, by appropriately setting the deposition rate and the etching rate, it is possible to form the high-quality thin film 10 on the substrate 13 having an uneven surface with good step coverage. The ratio of the deposition rate to the etching rate depends on the type of thin film 10 to be formed,
It is desirable to set it according to the film thickness, the degree of unevenness of the surface of the substrate 13, and the like. For example, a substrate with irregularities of about 1 μm on the surface
When forming a SiO ₂ film on 13, it is desirable to set the ratio of the deposition rate to the etching rate to 10: 1.

Further, as shown in FIG. 5, the target 21 is made of different material, for example, the W target 22 is set at the center and the Al target 23 is set around the target, and Ar ions emitted from the ion gun 12 are set, for example. By deflecting the flow of 16 sequentially, thin films 10a, 10b, 10a of different materials are formed on the substrate 13.
Alternatively, a plurality of layers may be formed. That is, first, while deflecting the Ar ions 16 at a large deflection angle, the Ar ions 16 are made to collide with the outer peripheral portion of the target 21, that is, the Al target 23, and
The sputtered particles 15 are punched out to form an Al film 10a on the substrate 13. Then, the deflection angle is reduced and Ar ions 16 are made to collide with the center of the target 21 to knock out the sputtered particles 15 'of W to form a W film 10b on the Al film 10a. After that, the deflection angle is increased again and Ar ions 16 are made to collide with the outer peripheral portion 23 of the target 21 to deposit sputtered particles 15 of Al on the W film 10b to form the thin film 10 having the three-layer structure on the substrate 13. Form on top.

Further, the flow direction of the sputtered particles 15 may be set to any direction such as a vertical direction or a horizontal direction. Furthermore, any shape may be used for the targets 11 and 21.

〔The invention's effect〕

As described above, the film forming method according to the present invention has a remarkable effect that a high quality thin film can be easily formed with a small apparatus.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a conventional film forming method, FIG. 2 is an explanatory view showing an embodiment of the present invention in which an electromagnet is used as the deflecting means, and FIG. 3 is an embodiment in which a deflecting plate is used as the deflecting means. FIG. 4 is an explanatory view showing an embodiment of the present invention in which the target is surrounded by an ion gun, and FIG. 5 shows an embodiment of the present invention using targets made of different materials. FIG. 10 ... Thin film, 11,18,21 ... Target, 12,19a, 19b ...
Ion gun, 13 ... Substrate, 14 ... Electromagnet, 15 ... Sputtered particles, 16,20 ... Ar ions, 17 ... Deflection plate, 22 ... Al target, 23 ... W target.

Claims (4)

[Claims] 1. A predetermined ion is emitted from an ion gun, the flow of the ion is made to collide with a target, and the sputtered particles knocked out from the target by the collision of the ion are opposed to each other at a predetermined distance from the target. Forming a film on the substrate, the ion gun is disposed close to an end of the target, and a direction substantially parallel to a normal line to the surface of the target and away from the target. A method for forming a film, characterized in that the predetermined ions are ejected onto the target, and the flow of the ejected ions is deflected to collide with the surface of the target. 2. The film forming method according to claim 1, wherein the means for deflecting the flow of ions is an electromagnetic field, and the ions are made to collide with the target while scanning the flow of ions. 3. The film forming method according to claim 1 or 2, wherein a plurality of the ion guns are arranged and used so as to surround the target. 4. A method according to claim 1, wherein a plurality of targets having different compositions or materials are used.
The method for forming a film according to item.